This invention concerns a process and devices for catalytic treatment (or hydrotreatment) of a fluid charge, and more particularly, for the demetallation, desulfurization, hydrotreatment and conversion or hydroconversion of hydrocarbons, in fixed or moving bed as explained hereafter.
The invention is particularly applicable to the catalytic treatments of liquid charges such as, for example, distillates obtained from heavy crude oils, residues of straight run and vacuum distillation of hydrocarbons, these treatments being generally effected in the presence of hydrogen and/or gaseous mixtures of high hydrogen content, over a bed of solid catalyst, with the catalyst being used as particles (extrudates, grains of various shapes, balls, etc . . . ).
During such catalytic treatments, often a quick deactivation of the catalyst is observed, which is due to the presence of catalytic poisons, the coke formation, the deposit of certain metals . . . , etc . . . .
This deactivation frequently requires the replacement of the whole or a part of the catalyst bed.